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View Full Version : Runs rough at hole shot


gatorguy
10-16-2011, 04:32 PM
So here's the deal I got my 97 ps205 with 489 hrs on it at the end of last season. It ran great and we only got to use it a few times before winterizing it last year. It now has 570hrs on it and ran great clear up until 2 trips ago.

The symptoms go something like this: Early morning skiing about 60 deg air 70 deg water. We idle at the ramp and out of the marina about 5 min total. I jump in to ski tell my son to hit it (up to now nothing is different than any other time we've gone out except it is a little colder) and the engine bogs down. It stayed bogged until he let off the throttle. I told him to try again and this time ease into it, and it worked just fine. After a few minutes I crashed and it hesitated again during the hole shot however not as bad. The hesitation improved until it was almost just a little hiccup that someone new to the boat may not notice.

The next trip out was exactly the same except I ran it hard for a few minutes before I tried to ski. I started and stopped a handful of times to get the engine up to temp and try to work what ever it was through the system. I did notice that while it got better, the engine temp seemed to be independent of the problem. What I mean is that if the worst problem was a 10/10 before the temp was at 160 it was still an 8/10 when the engine was at proper temp and would continue to improve to about a 2/10 as I ran in more over the next hour.

I had just refueled before this happened the first time so I guess it could be bad gas, but I would guess that would run bad the whole time and get worse at high RPM. Fuel filter was changed when I winterized, so it is at about 60hrs.

And no, I don't know what my fuel pressure is. I do know I still can hit 40-41mph which was my old top speed.

So, any ideas?:confused:

cmarty123
10-16-2011, 08:45 PM
I have a 95 w/ 350 tbi. I would replace fuel filters. I know I replaced the fuel filters at the beginning of the season. I put about 60 hours on the engine and it started to give me fits similar to yours. I replaced filters and it runs great. I believe the ethanol really messes things up. I'm going to start putting a stabiizer in...

JimN
10-16-2011, 09:59 PM
So here's the deal I got my 97 ps205 with 489 hrs on it at the end of last season. It ran great and we only got to use it a few times before winterizing it last year. It now has 570hrs on it and ran great clear up until 2 trips ago.

The symptoms go something like this: Early morning skiing about 60 deg air 70 deg water. We idle at the ramp and out of the marina about 5 min total. I jump in to ski tell my son to hit it (up to now nothing is different than any other time we've gone out except it is a little colder) and the engine bogs down. It stayed bogged until he let off the throttle. I told him to try again and this time ease into it, and it worked just fine. After a few minutes I crashed and it hesitated again during the hole shot however not as bad. The hesitation improved until it was almost just a little hiccup that someone new to the boat may not notice.

The next trip out was exactly the same except I ran it hard for a few minutes before I tried to ski. I started and stopped a handful of times to get the engine up to temp and try to work what ever it was through the system. I did notice that while it got better, the engine temp seemed to be independent of the problem. What I mean is that if the worst problem was a 10/10 before the temp was at 160 it was still an 8/10 when the engine was at proper temp and would continue to improve to about a 2/10 as I ran in more over the next hour.

I had just refueled before this happened the first time so I guess it could be bad gas, but I would guess that would run bad the whole time and get worse at high RPM. Fuel filter was changed when I winterized, so it is at about 60hrs.

And no, I don't know what my fuel pressure is. I do know I still can hit 40-41mph which was my old top speed.

So, any ideas?:confused:

Have you looked at the flame arrestor? If it's dirty, it won't run well, hot or cold. Also, make sure the coolant temperature sensor plug is secure (the two-wire plug, not the one-wire plug). Also, check the resistance of the two-wire coolant temperature sensor- if it's lower than a few thousand Ohms when it's cold, it's bad. OTOH, if you see >100K Ohms when the engine is at normal operating temperature, it's bad.

Check the fuel pressure. Period.

How old are the plugs, cap and rotor? Inspect them thoroughly. If you need new, buy from O'Reilley's or another store that sells Borg-Warner cap & rotor- they come with a lifetime warranty. Buy plug wires with the same warranty. It's well worth any extra cost. Use the AC spark plugs, don't cross-reference.

mikeg205
10-16-2011, 10:06 PM
run some seafoam in the tank and thru the TBI... plus clean the fuel filters.as well...

CoreyWakeboard
10-22-2011, 03:12 PM
Had similar issues and it was the Risers around the 550 hours mark. Water was dripping into the cylinders and getting water on the spark plugs. Tell tell signs were rusted spark plugs and there was lag during hole shots. Replaced the Risers and all was fine.